1. Field of the Invention
The present invention relates to video editing technology for concatenating plural pieces of video data.
2. Description of the Related Art
In recent years, it has become common to provide various devices, such as a digital video camera, a digital camera, a digital single-lens reflex camera, a mobile phone, a personal digital assistant, and a mobile music player, with a movie-capturing function. The increased capacity of data storage media such as hard disk drives and memory cards, has caused a significant increase in the amounts of video data possessed by individuals. Furthermore, there is an increasing number of opportunities for captured videos to be viewed by an unspecified number of users, as a result of the spread in services that allow users to upload their video data to the Internet and share and view the data with other users, an increasing number of network-compatible TVs, and so on.
Generally, in order to view a video captured by a video camera or the like, the viewing time must be the same as the amount of time spent to capture a video. In view of this, a user selectively views a captured video by, for example, directly selecting a time interval of video data to be viewed (hereinafter referred to as a “target viewing interval”) with use of the random access function called the “chapter menu” function, the thumbnail display on a file-by-file basis or the like, or fast forwarding video data where appropriate during playback.
However, many users not only select target viewing intervals in video data as described above, but also perform editing on video data itself by, for example, extracting target viewing intervals from video data and concatenating those intervals. An example of basic video editing processing is creating an edited movie by concatenating a plurality of target viewing intervals in video data and performing various types of processing as necessary, such as combining graphic videos, providing visual effects (such as a transition effect) to the concatenated portions between the intervals, and adding background music.
Such video editing processing requires expertise regarding video and execution of operations using special tools, so it is difficult for ordinary users. In addition, selecting necessary pieces of video data or intervals from time-based video data is a troublesome operation.
In view of this, technology for automatically performing video editing using a template file is known as technology that automatically generates an edited movie in which plural pieces of video data are concatenated (for example, Japanese Patent Laid-open No. 2009-55152). Material boxes in which video data is to be inserted, effects, background music, and transitions are pre-defined according to a time code in the template file. By analyzing metadata of each material box in the template file as well as metadata of video data, a video editing apparatus inserts video data that has the same metadata as that in the template file in each material box in the template file.
However, there are the following problems with the above-described video editing processing using the template file. For example, a great difference in the subject size between two videos, in which the same subject moves continuously, causes the speed of movement of the subject (moving speed) to look different. In the case where two such videos are concatenated and the resultant edited movie is played back, the sequence of the movie looks unnatural in particularly the concatenated portion and accordingly gives a feeling of visual unpleasantness to the user. There is also a problem in that the occurrence of a change in the movement of the subject, which is unexpected to the user, causes the eye movement of the user to increase and accordingly places a physical burden such as eyestrain on the user.
The present invention enables two pieces of video data that include the same subject to be concatenated with each other such that the movement of the subject becomes a natural sequence therebetween, thereby reducing the feeling of visual unpleasantness.